Chinese human rights lawyers arrested during a recent crackdown have pleaded guilty to a range of offenses including inciting disorder, the country's main Communist Party newspaper reported on Sunday.

Nine lawyers and four other staff members at the Fengrui legal firm have been charged with disrupting trial proceedings and violating court rules. Zhou Shifeng, the director of the firm, has pleaded guilty, the People's Daily reported.

Nearly 200 lawyers and activists have been detained or questioned during a campaign launched by public security bureaus this month, with the Communist Party maintaining a zero-tolerance approach to dissent.

Human rights group Amnesty International called the crackdown "unprecedented" and said on Thursday 31 of those detained remained in custody.

The People's Daily accused the group from the Fengrui firm of orchestrating protests outside courts to help secure favorable verdicts for clients. The Xinhua state news agency, in a separate report on Sunday, described such behavior as "very close to blackmailing".

The People's Daily said many of the suspects had admitted to hyping up and politicizing ordinary legal cases in order to attract international attention.

"Many of the criminal suspects have confirmed that the Fengrui legal firm pursued sensitive cases, and if they were not sensitive or prominent enough, they would think of ways to stir them up," the People's Daily said.

Reuters could not reach Zhou or other lawyers with the Fengrui firm on Sunday.

The Fengrui law firm has represented several high profile clients such as the ethnic Uighur dissident Ilham Tohti and Zhang Miao, a news assistant at German newspaper Die Zeit who was recently detained for more than six months.

The People's Daily, the official organ of the Chinese Communist Party, said police were recently ordered to smash a "criminal gang" of lawyers accused of using the Beijing-based Fengrui as a platform to "stir up public disorder".

Among those arrested were the prominent human rights lawyer Wang Yu and Wu Gan, a former employee of Fengrui who blogs on human rights and free speech issues.

Wang has previously defended Li Tingting, a prominent rights activist, as well as Cao Shunli, an activist who died in detention after being denied medical treatment.

State media said preliminary police investigations had shown that since July 2012, the lawyers "plotted to hype up more than 40 legal cases, seriously interfering with normal judicial activities and disrupting social order".

It also accused the lawyers of disseminating attacks on the Communist Party and the Chinese government and bringing discredit to the judicial system.